The potential energy of a point particle of mass $m$ undergoing rectilinear motion along the x -axis is given by
$V(x)=A x+B x^2$
What is the maximum speed attained by the particle if it starts from rest at $x=\frac{A}{B}$ ?

• A

  $\frac{A}{\sqrt{2 B m}}$
• B

  $\frac{2 A}{\sqrt{B m}}$
• C

  $\sqrt{\frac{2}{B m}} A$
• Correct answer
  D

  $\frac{3 A}{\sqrt{2 B m}}$

Hence, the correct answer is option: 'D'.